20" x 25" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 22.5"w X 27.5"h] Powder-Coat 5" - SEE BELOW IN

5" - SEE BELOW IN DESCRIPTION How To Measure A Grille

+ Product Details Size - 12"w X 36"h is the size for the duct opening measurement only

+ Product Details Size - 12"w X 8"h is the size for the duct opening measurement only

If you are looking to enhance your project with a top-of-the-line unit

+ Product Details Size - 10"w X 12"h is the size for the duct opening measurement only

20" x 25" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 22.5"w X 27.5"h] Powder-Coat 5" - SEE BELOW IN+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 25" OR 25" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 27. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 75" x 24. 75" x 1" Premium Airflow Efficiency High performance cube core eggcrate design allows 95% airflow efficiency, reducing energy costs and maximizing HVAC system lifespan. Durable, Rust Free Aluminum